Method and apparatus for treating human remains

ABSTRACT

A process for treating a human remains comprises the steps of subjecting the remains to pyrolysis in a pyrolysis chamber under conditions that convert the particulate material to biochar remains.

TECHNICAL FIELD

The invention relates to a method and apparatus for treating humanremains. In particular, the invention relates to a method and apparatusfor treating the human remains for burial or other means of disposal.

BACKGROUND ART

Traditionally, human remains are stored after death for a period of timeprior to commitment. In most cases, the remains are initially embalmed,which involves draining the blood from the body and replacing it with anembalming fluid such as formalin, which serves to delay the decayingprocess. The remains are then generally either buried in a cask in theground, or cremated.

There are a number of problems associated with these establishedpractices. The problems associated with burial include ecologicalproblems, namely that the toxins in the body eventually make their wayinto the ground and water table. These toxins include formalin, which istoxic and has recently been recognised as a carcinogen, mercury (whichis present in dental fillings), and numerous other carcinogens. Inaddition, the body may also contain microbiological pathogens, includingbacteria such as E. coli and S. aureus, viral pathogens and prions. Afurther problem associated with burial is that the conditions preventmouldering of the body, with the result that the body rots under theinfluence of sulphur-producing bacteria, taking 80 years or more tofully decompose. Cremation is perceived as a cleaner, and moreecologically friendly, commitment process, and involves burning theremains at a high temperature of approximately 900° C. for a period ofone to a few hours, depending on the size of the body. Any remainingskeletal bones may be crushed to provide the final ash, which is placedin an urn for final disposition. This is an energy intensive process,producing flue gases which are released into the atmosphere. These fluegases are known to include many toxins, including mercury.

Various attempts have been made to provide more ecologically, andenvironmentally, friendly methods of treating and disposing of humanremains. For example, the literature includes details of numerousalternative processes, where the human remains are chilled, generally inliquid nitrogen, then fractured into particulate matter, and thenfreeze-dried to remove water, before finally being buried in shallowground to allow aerobic decomposition take place. Examples of this priorart include the following documents:

U.S. Pat. No. 4,067,091 (Backman—1976)—describes a process of treatinghuman remains which involves cryogenically cooling the remains in liquidnitrogen, size reducing the remains using mechanical means,freeze-drying the particulate matter to remove about 95% of water, anddepositing the freeze-dried material in a storage container.

International (PCT) Application No: WO01/03516 (Max World TechnologyInc—1999)—describes a process for treatment of biological waste similarto that of Backman (above) except that prior to cryogenically coolingthe biological waste is subject to a dehydration step where at least 80%of water is removed. The process of the invention is intended for usewith food, animal waste etc; use with human remains is not suggested.

European Patent Application No: EP1234151 (Promessa AB—2000)—describes aprocess for treating organic matter, including vegetable and animalwaste, which employs cryogenically cooling and freeze-drying steps, andan additional intermediate step in which the chilled matter is subjectedto a splitting process in which the chilled matter is perforated withhigh pressure water, steam or oil, or a high energy laser.

International (PCT) Patent Application No: WO2007/053078 (Wiigh-Masak etal—2006)—this application addresses the problems associated with,mouldering of remains following burial, and provides coffins having aspecific C:N:P ratio suitable for promoting mouldering of the remainsfollowing burial. The process for treating the remains described in thisApplication includes cryogenically cooling, size reduction andfreeze-drying.

International (PCT) Patent Application No: WO2008/147292 (Ecof-FinGmbH—2008)—this process describes a method in which remains are put in acoffin that includes a mineral based filler and a polyolefin binder,cryogenically cooling the body and coffin, disintegration of the chilledmatter using mechanical or ultrasound means, and freeze-drying thedisintegrated matter. The problem that the invention addresses is thelow pH of human remains that result from conventional alternativeprocesses such as promession, which causes acidification of the soil;this process overcomes this problem.

International (PCT) Patent Application No: WO2008/116820 (DEmaco HollandBV—2008)—this process describes a method for treatment of human oranimal remains including the steps of cryogenically cooling the body,size reduction of the chilled matter using mechanical or ultrasoundmeans, and freeze-drying the size-reduced matter. The problem that theinvention addresses is the inefficiency associated with freeze-dryinghuman remains (time required, energy input), and the suggested solutionis to dehydrate the remains (either prior to cooling or after sizereduction) at a temperature higher than body temperature (generally lessthan 100° C.).

All of the above-referenced processes employ freeze-drying as a means ofremoving water from the remains. However, freeze-drying is recognised asbeing an energy intensive process, which is inefficient in terms of theprocess time and the amount of energy required to adequately removewater from the body. Moreover, it has been recognised that freeze-dryingfails to kill all microbial pathogens, including virus and prions, whichresults in these microorganisms remaining in the dried tissue andgenerally being put back into the environment. Attempts have been madeto address this issue by chemical (peroxide) treatment of thefreeze-dried particulate matter, however while this has partiallyaddressed the microbial contamination issue, it results in more toxicchemicals being employed in the process. Additionally, the methods ofthe prior art have failed to address the issue of formalin and mercurycontamination.

It is also recognised that freeze-drying does not remove all water fromthe remains, and generally anything between 10% to 30% of the water inthe remains will not be removed during freeze-drying. This also meansthat a substantial amount of embalming fluid is not removed from theremains, resulting in this embalming fluid being buried in the groundwith the remains. The most common constituent of commercial embalmingfluid, formalin, which is a solution of formaldehyde in water, is toxicand a known carcinogen. Thus, conventional burial of human remains, andalso known alternative processes such as promession, lead toenvironmental contamination with a known carcinogen.

It is an object of the invention to overcome at least one of theabove-referenced problems.

STATEMENTS OF INVENTION

Broadly, the invention provides a process for treating human remainscomprising the steps of subjecting the remains to pyrolysis in apyrolysis chamber under conditions that convert the remains to biocharremains.

Surprisingly, the process results in remains (biochar) that is free frommercury and other heavy metals, the toxic metals having been removedfrom the remains as a vapour to be subsequently condensed and storedaway from the environment. Furthermore, the process of pyrolysis resultsin all microbial pathogens being destroyed.

In a preferred embodiment, the process comprises a further step ofoxidation of the biochar subsequent to the pyrolysis step. This furtherstep results in any volatile hydrocarbons in the biochar being oxidised,and also the removal of tar from the biochar by oxidation whichfacilitates subsequent handling of the biochar.

Suitably, the remains are dried prior to pyrolysis. Methods of dryingthe remains are described below, and include evaporative drying andfreeze-drying. Other methods will be apparent to those skilled in theart. In the drying step, aqueous fractions, mainly water but also toxicaqueous fractions, for example formalin, are removed from the remains toreduce the water content of the remains. Typically, the remains aredried until the water content of the remains is 1-20%, preferably 5-10%,more preferably 7-9%, and ideally about 8% (w/w).

Typically, the remains are fragmented prior to pyrolysis. Thefragmentation step may take place after drying, or preferably prior todrying. Methods of fragmenting the remains are described below, andother methods will be apparent to those skilled in the art.

Ideally, the remains are chilled prior to fragmentation by subjectingthe remains, ideally the intact remains, to a cryogenic environment toreduce the temperature of the remains to a core temperature of −20° C.or below.

In a preferred embodiment, the process involves the steps of subjectingthe remains to a cryogenic environment to reduce the temperature of theremains to a core temperature of −20° C. or below, subjecting the frozenremains to a fragmentation step to provide a frozen fragmented material,and drying of the frozen fragmented material ideally by evaporativedrying, typically to a water content of 5-10% (w/w).

Compared with the prior art methods of treating human remains, themethod of this preferred embodiment of the invention has a number ofadvantages. First, the method of the invention employs an initialevaporation step which removes a substantial amount of water from thecorpse, followed by a pyrolysis step which converts the organic matterto biochar and, combustible gas by-products. This results in the energyneeds of the process being reduced as the combustible gas by-productsmay be re-cycled to power the evaporation and/or pyrolysis steps.Further, the step of evaporation which is carried out prior to pyrolysisgreatly reduces the amount of energy required to convert the particulatematter to biochar.

Thus, in a preferred embodiment of the invention, the process includes astep of removing gas by-products from the pyrolysis chamber. Examples ofgas by-products generated during pyrolysis include methane. The gasby-products may be stored for recycling, or they may be directlyrecycled to power the evaporation and/or pyrolysis steps. In someembodiments, the gas by-products are fractionated to separatecombustible gases from non-combustible gases.

The temperature and time of pyrolysis may be varied, but generally thetemperature of operation will be at least 800° C., and generally higher.In one embodiment, pyrolysis is carried out at a temperature of 900° C.,for a typical period from 30 minutes to four hours. Further, it will beappreciated that if a lower temperature is employed, the pyrolysis timemay be increased, and vice-versa. It will also be appreciated that thepyrolysis conditions may be varied depending on the amount ofparticulate and the desirable features of the biochar to be produced(which of course depends on the size and composition of the remains).

Generally, the process of pyrolysis includes an initial step of hydrouspyrolysis and a subsequent step of anhydrous pyrolysis.

Generally, the drying step reduces the water content of the remains by87-97%, preferably about 95%. This ensures that the remains include somewater (generally about 5-10%, preferably 7-9%, and ideally about 8%(w/w) is desired) so that the initial pyrolysis step is anhydrouspyrolysis, ideally ablative flash pyrolysis. Preferably, drying isachieved by heating the remains, which is generally in the form of afrozen fragmented material, ideally by evaporative drying, to atemperature of generally above 100° C., typically about 150° C.- to 250°C., for a period of time suitable to reduce to water content of theremains to the desired level. Evaporated liquid is generally continuallyremoved from the evaporation chamber, and is ideally condensed andeither stored or further processed. In one embodiment, the liquid isdistilled to remove toxic components such as, for example, formalin,which may be recycled to provide energy for the pyrolysis process. Inanother embodiment, the water removed from the particulate is subjectedto a flash evaporation step.

In a preferred embodiment of the invention, the process of the inventionincludes a further step of separating mercury (optionally includingother heavy metals) from the gaseous products of pyrolysis. This may beachieved by means of a water based cleaning process, where the mercury(and/or any other condensable toxic vapour) is removed by means of awater spray system, whereby the flue gas is sprayed with water and heavymercury vapour (and any other condensable toxic vapour) will condenseand be recovered. In another embodiment of the invention, mercury andother condensable toxic vapours may be removed from the combustion gasesbefore they are allowed to exhaust to atmosphere. It will be appreciatethat there are other methods of removing electrically conducting gas orvapour such as mercury from a mixture of other components.

Typically, the invention includes a further step of depositing thebiochar remains in a container which may be sealed against ambient air.

The invention also provides a process for treating human remains toremove mercury or other heavy metals from the remains comprising thestep of subjecting the remains to pyrolysis in a pyrolysis chamber underconditions that convert the particulate material to biochar remains,wherein flue gases expelled from the pyrolysis chamber are sprayed withan aqueous liquid, typically water, to condense the mercury or othermetals for recovery.

Preferably, the method involves the steps of:

-   -   subjecting the remains to a cryogenic treatment to reduce the        core temperature of the remains to a temperature of −20° C. or        below; subjecting the frozen remains to a fragmentation step to        provide a frozen fragmented material;    -   removing water from the frozen fragmented material to reduce the        water content of the frozen fragmented material, ideally to        5-10% water content (w/w);    -   subjecting the partially de-watered fragmented material to        pyrolysis in a pyrolysis chamber under conditions that convert        the particulate material to biochar remains; and    -   treating the gases generated as a result of the pyrolysis        process to remove the mercury or other heavy metals from the        gases.

Preferably, the gases are subjected to a water based spray cleaning stepto condense the heavy metals from the gases. However, an electrostaticprecipitation process may also be employed to remove the heavy metals ormercury from the gases. Ideally, the biochar remaining is free frommercury.

The invention also provides an apparatus for treating a human remainscomprising a cryogenic chamber for subjecting the remains (generallyintact remains) to cryogenic conditions, optionally means for providinga cryogenic fluid to the cryogenic chamber, a fragmentation apparatusadapted to receive the remains from the cryogenic chamber and capable offragmenting the remains to a fragmented material, a drying chambercapable of removing liquid from matter contained therein (ideally byevaporative drying) and removing the liquid, and a pyrolysis chamberadapted for thermally decomposing the particulate matter in the absenceof oxygen.

It will be appreciated that the apparatus of the invention may beemployed to treat animal as well as human waste, and may also beemployed to treat biological material such as, for example, medical andclinical waste and biohazardous waste.

It will be appreciated that the drying chamber and pyrolysis chamber maybe provided as a single chamber, adapted to perform an initialde-watering step and a subsequent pyrolysis step.

In this embodiment, typically, the drying chamber is operably connectedto a source of inert gas and includes means for charging the chamberwith this inert gas. This enables a process of pyrolysis to occur, ascharging the chamber with inert gas ensures that no oxygen remainswithin the chamber.

In one embodiment, the process of the invention includes a flashevaporation apparatus operably connected to the drying chamber andcapable of performing flash evaporation on the evaporated water removedfrom the drying chamber.

Preferably, the drying chamber may be operably connected to a gasstorage device and includes means for removing combustible gasby-products of the pyrolysis process during the pyrolysis process andstoring the gas by-products in the gas storage device.

Generally, the drying chamber comprises a burner for heating thechamber, wherein the apparatus includes means for re-cycling gas fromthe gas storage device to the burner for heating the drying chamber. Insome embodiments of the invention the gas storage device is omitted andthe gaseous by-products of the pyrolysis are directly fed back tocombustion for heating the pyrolysis chamber and/or the drying chamber.

Suitably, the apparatus includes a water spray adapted to remove heavymetal vapours, especially mercury, from the evolved gases.

In another aspect, the invention provides a process for treating humanremains to remove embalming fluid from the remains comprising the stepof treating the remains with heat to evaporate volatile components ofthe embalming fluid and optionally water vapour from the remains. Themethod of the invention results in remains which are substantially freeof toxic volatile components such as formaldehyde, thus preventing thesetoxic components being returned to the environment.

Typically, the volatile components are recovered by condensation ordissolution in a solvent.

Suitably, the recovered volatile components are recycled to power theevaporation step, or another step in the process such as pyrolysis orfragmentation.

In one embodiment, the dehydrated remains are subjected to pyrolysis toconvert the remains to a biochar.

Preferably, the recovered volatile components are recycled to power theevaporation step, the pyrolysis step, or both.

Typically, the recovered volatile components are stored prior torecycling.

In a preferred embodiment, the remains are fragmented prior to theevaporation step.

Suitably, the remains are subjected to a cryogenic environment to reducethe core temperature of the remains to a temperature below −20° C. priorto fragmentation.

Preferably, the evaporation step reduces the water content of theremains to 1-20% (w/w), more preferably to 6-10% (w/w), and ideally toabout 8% (w/w).

Suitably, the volatile components, evaporated water vapour and otherliquid by-products of the evaporation step are combined prior toseparation by distillation.

Typically, the volatile components, evaporated water vapour and liquidby-products of the pyrolysis step are combined prior to separation bydistillation.

Thus, in a preferred embodiment, the invention provides a process fortreating human remains to remove embalming fluid from the remainscomprising the steps of subjecting the remains to a cryogenicenvironment to reduce the core temperature of the remains to atemperature below −20° C., and subjecting the chilled remains to a sizereduction step to provide a chilled particulate material. Volatilecomponents of embalming fluid and water vapour (including aqueousfractions from the remains) are then evaporated from the chilledparticulate material to reduce the water content of the chilledparticulate material, generally until about 8% (w/w) is retained in theremains, and the partially de-watered particulate is then ideallysubjected to pyrolysis to generate biochar and gaseous by-products ofpyrolysis. The vapour fractions, including formaldehyde gas arepreferably condensed and subsequently distilled to remove toxicmaterials from the environment, including formaldehyde.

The term “embalming fluid” as employed herein should be understood tomean the fluid that is employed by undertakers to preserve and fix acorpse prior to burial or commitment. These fluids exist under varioustrade names, and contain active ingredients usually including but notlimited to alcohols, phenols and formalin, which is a solution offormaldehyde gas in water. Thus, process of the invention involvesremoval of formalin from the body as part of the aqueous fractions(which may be removed as formalin vapour, water vapour, and gaseousformaldehyde), and then subsequent distillation of the aqueous fractionsto separate out and remove the formaldehyde for recycling.

The process of the invention, including the evaporation and pyrolysissteps, provides remains that are effectively free of water and embalmingfluids. Thus, the problem of toxic or carcinogenic embalming fluids, ortoxic or carcinogenic components thereof, being put back into theenvironment is obviated. The process of the invention also results inrecovery of embalming fluids, or components thereof, in a purified form,and thus allows for re-cycling of the toxic components away from theenvironment.

Generally, the evaporation step reduces the water content of the remainsto about 8% by weight. This ensures that the remains include some water(generally about 5-15%, 8-12%, and ideally about 8% is desired) tofacilitate the pyrolysis process step. Evaporation is achieved byheating the remains to an elevated temperature (i.e. a temperaturegreater than body temperature) of generally above 100° C., typicallyfrom 150° C. to 250° C., for a period of time suitable to reduce towater content of the remains to approximately 8%. Evaporated aqueousfractions are generally continually removed from the evaporationchamber, and are then optionally condensed before further processing. Inan embodiment in which distillation is performed on both the aqueousfractions and the liquid by-product stream of pyrolysis, the aqueousfractions and the liquid by-products may be combined prior todistillation. In another embodiment, the water removed from theparticulate is subjected to a flash evaporation step.

In a preferred embodiment of the invention, the process includes a stepof removing gas by-products from the pyrolysis chamber. Examples of gasby-products generated during pyrolysis include carbon containing gasessuch as CO₂, CO, and methane. The gas by-products may be stored forrecycling, or they may be directly recycled to power the evaporationand/or pyrolysis steps. In some embodiments, the gas by-products arefractionated to separate combustible gases from non-combustible gases,wherein the combustible gases may be recycled to power the evaporationand/or pyrolysis steps.

The temperature and time of pyrolysis may be varied, but generally thetemperature of operation will be at least 250° C., 300° C., 350° C.,400° C., 450° C., 500° C., 550° C., 600° C., 650° C., 700° C., or 800°C. In one embodiment, pyrolysis is carried out at a temperature of from300° C. to 1200° C., 400° C. to 1200° C., 500° C. to 1200° C., 600° C.to 1200° C., 700° C. to 1200° C., or 800° C. to 1200° C. Suitably,pyrolysis is carried out for a period of from 1 minute onwards, 1-24,2-12, 3-10, 4-8 hours. Further, it will be appreciated that if a lowertemperature is employed, the pyrolysis time may be increased, andvice-versa. It will also be appreciated that the pyrolysis conditionsand duration may be varied depending on the amount of particulate (whichof course depends on the mass and volume of the funereal remains).

In a preferred embodiment of the invention, the process of the inventionincludes a further step of separating mercury or other heavy metals fromthe biochar remains. This may be achieved by means of a condensationprocess, whereby the vaporised mercury is condensed by lowering itstemperature to below 450° C. in temperature and the mercury (and anyother vaporised metals present) will condense and be recovered. In oneembodiment of the invention this may be achieved by using a waterscrubbing process to lower the temperature of the flue gases. In anotherembodiment, a heat exchanger is employed to recover energy from the fluegases, thereby reducing the gas temperature to below 450° C. andcondensing the mercury vapour from the flue gas stream.

Typically, the invention includes a further step of depositing thebiochar remains in a container which may be sealed against ambient air.

The invention also provides an apparatus suitable for treating humanremains comprising (a) a heating chamber adapted to receive humanremains and heat the remains to evaporate water vapour and volatilecomponents of embalming fluids from the remains, (b) optionally apyrolysis chamber adapted to receive the dehydrated remains, subject thedehydrated remains to pyrolysis, and remove a liquid fraction by-productfrom the remains, (c) a distillation apparatus adapted to receive theevaporated water vapour and volatile components from the heating chamberand optionally the liquid fraction by-products from the pyrolysischamber and distil the evaporated water vapour, volatile components andoptionally the liquid fraction by-products to separate out and recoverthe volatile components, and (d) optionally a volatile component storagevessel adapted to receive and store the recovered volatile component.

The invention also provides an apparatus suitable for treating humanremains comprising (a) a heating chamber adapted to receive humanremains and heat the remains to evaporate water vapour and volatilecomponents of embalming fluids from the remains, (b) a pyrolysis chamberadapted to receive the dehydrated remains, subject the dehydratedremains to pyrolysis, and remove a liquid fraction by-product from theremains, (c) a distillation apparatus adapted to receive the evaporatedwater vapour and volatile components from the heating chamber and theliquid fraction by-products from the pyrolysis chamber and distil theevaporated water vapour, volatile components and the liquid fractionby-products to separate out and recover the volatile components, and (d)optionally a volatile component storage vessel adapted to receive andstore the recovered volatile component.

Preferably, the apparatus includes a condensation apparatus adapted tocondense the evaporated water vapour and volatile components prior todistillation.

In one embodiment, the heating chamber and the pyrolysis chamber areprovided as a single chamber adapted to perform evaporation andsubsequently pyrolysis on the human remains.

Typically, the apparatus further includes a flash evaporation apparatusoperably connected to the heating chamber and capable of performingflash evaporation on the evaporated aqueous fraction removed from theheating chamber.

Suitably, the pyrolysis chamber is operably connected to a source of aninert gas and includes means for charging the chamber with an inert gas.

Typically, the pyrolysis chamber is operably connected to a gas storagedevice and includes means for removing combustible gas by-products ofpyrolysis and storing the gas by-products in the gas by-products storagedevice.

In a preferred embodiment, the pyrolysis combustion chamber comprises aburner, wherein the apparatus includes means for re-cycling thegas-by-products from the pyrolysis retort device to the combustionchamber burner for heating the pyrolysis chamber.

In another aspect, the invention provides an apparatus for treatinghuman remains to remove embalming fluids, or toxic or carcinogeniccomponents thereof, from the corpse, the apparatus comprising:

a cryogenic chamber adapted to receive human remains and subject them tocryogenic conditions;

-   -   a size reduction device adapted to receive the chilled remains        from the cryogenic chamber and size reduce those remains to a        chilled particulate material;    -   a heating chamber adapted to receive the particulate from the        size reduction device, evaporate volatile components and        optionally water vapour from particulate material and remove the        volatile components and water vapour;    -   a pyrolysis chamber adapted to receive the at least partially        de-watered particulate material from the heating chamber,        subject the particulate matter to pyrolysis, and remove a        gaseous by-product of pyrolysis;    -   a distillation apparatus adapted to receive the evaporated        volatile components and optionally water vapour from the heating        chamber and subject them to distillation to separate out and        recover some toxic materials; and    -   a storage vessel for receiving formaldehyde gas from the        distillation apparatus and appropriately storing the material        for recycling.    -   Suitably, the apparatus comprises a dispensing apparatus for        placing the remaining bio char in an urn or pod for final        disposition.

Preferably, the pyrolysis chamber is operably connected to a source ofan inert gas and includes means for charging the chamber with an inertgas. This enables a process of pyrolysis to occur, as charging thechamber with inert gas ensures that no oxygen remains within thechamber.

Suitably, the pyrolysis chamber is operably connected to a gas storagedevice and includes means for removing combustible gas by-products ofpyrolysis and storing the gas by-products in the gas by-products storagedevice. Typically, the pyrolysis chamber comprises a burner, wherein theapparatus includes means for re-cycling the gas-by-products from thepyrolysis chamber to the burner for heating of the pyrolysis chamber tothe correct temperature, typically about 900° C.

In a preferred embodiment, the apparatus comprises a condensationprocess adapted to receive combustion gases from the heating chamber andremove heavy metals such as mercury from the gas by means of a heatexchanger or a water scrubbing process. It will be appreciated thatother methods of removal of metal vapour such as electrostaticprecipitation might be employed instead of, or as well as the waterscrub or heat exchanger.

In this specification, the term “human remains” should be understood tomean a deceased human body, typically intact.

Although not the primary focus, it will be appreciated that the methodsof the invention may be employed generally with biological matter, forexample with animal remains, for example, agricultural animals such ascows, sheep, goats and poultry, domestic animals such as cats, dogs, andbirds, and larger animals such as elephants and giraffes, where theremains are, typically, substantially intact, and clinical and medicalwaste, biohazardous waste and body parts.

In this specification, the term “cryogenic treatment” refers to bringingthe remains into contact with a cryogenic fluid, such as nitrogen orhelium, having a temperature of not greater than −100° C., ideally notgreater than −150° C. The term “cryogenic fluid” should be understood tomean a fluid that exists in a liquid or gaseous form at least −100° C.,preferably at least −150° C.

In this specification, the term “core temperature” should be understoodto mean the temperature at the core of the remains. In humans, thiswould be, for example, the temperature in the centre of the torso.Generally this will be the highest temperature recorded within theremains during the cooling process.

In this specification, the term “fragmentation” should be understood tomean the process in which a mass is size-reduced into smaller particles.The term “fragmented material” should be understood to mean composed ofparticles that are produced as a result of size reduction orfragmentation. The particulate may be of any size, but generally has anaverage particle size of 10 mm or less (i.e. the particles have adiameter when measured at their widest of 10 mm or less). Ideally, theparticulate has a particle size of less than 10 mm. Examples offragmentation of frozen human remains are described in the documentsreferenced above, and include mechanical fragmentation, milling,grinding, exposure to ultrasonic sound waves, or exposure to pressurewaves. When the human remains have been frozen to a core temperature of−20° C. or below, the remains will be very brittle and prone toshattering upon the application of force.

In this specification, the term “pyrolysis” is an art-recognised termand should be understood to mean the process of thermochemicaldecomposition of matter in the absence of oxygen. It is generallyachieved by heating in the absence of oxygen to a temperature of atleast 300° C., and often much higher, resulting in the long chainhydrocarbons being converted to short chain hydrocarbons, and a greatincrease in the elemental carbon content of the matter. In the processof the invention, the matter is converted into “biochar”, which shouldbe understood to mean the matter that remains when biomass is subjectedto pyrolysis. During the pyrolysis process, combustible gases areproduced, and these gases may be removed from the pyrolysis chamber, andoptionally combusted to power the pyrolysis process. Generally, thesegases are lower alkane gases, such as methane or ethane. In oneembodiment, the gas by-products removed from the pyrolysis chamber maybe fractionated to separate the lower alkanes from other gases produced.In another embodiment, the gases removed may be stored. Methods andapparatus for performing pyrolysis are described in the literature, forexample in WO2012012191 and US20110278149.

In this specification, the term “heavy metals” should be understood tomean mercury, cadmium, lead, chromium, arsenic, gold, silver andplatinum.

In this specification, the term “flash evaporation” should be understoodto mean an evaporation process when a saturated liquid stream undergoesa reduction in pressure by passing through a throttling valve or otherthrottling device.

In this specification, the term “inert gas” should be understood to meana gas that does not undergo oxidation or hydrolysis reactions, forexample nitrogen.

In this specification, the term “domestic animal” should be understoodto means domestic pets, for example, dogs, cats, and rodents.

In this specification, the term “biological material” should beunderstood to mean waste material that contains biological subjectmatter such as blood, serum, cells, tissue, organs or limbs. Examples ofsuch material include clinical and medical waste material, waste fromhospitals, and other types of biohazardous waste.

In this specification, the term “aqueous components” should beunderstood to mean water, aqueous solutions such as embalming fluids(i.e. formalin and polyethylene glycol-based embalming solutions), andcomponents of embalming fluids that are susceptible to evaporation (forexample formaldehyde, alcohols, phenols etc.).

In this specification, the term “human remains” should be understood tomean a deceased human body, typically intact.

The term “fractional distillation” should be understood to mean theprocess of separating components (fractions) of a liquid mixture on thebasis of their differing boiling points. Thus, a fluid containing amixture of water and formalin can be separated into its components partsusing fractional distillation, where the water will boil at or about100° C. and the formaldehyde will boil off at or about 96° C., dependingon its concentration in the formalin.

The term “particulate” should be understood to mean composed ofparticles that are produced as a result of size reduction. Theparticulate may be of any size, but generally has an average particlesize of 10 mm or less (i.e. the particles have a diameter when measuredat their widest of 10 mm or less. Ideally, the particulate has aparticle size of less than 40 mm, 30 mm, 20 mm, 15 mm or 10 mm.

In this specification, the term “electrolysis” should be understood tomean the decomposition of water into hydrogen and oxygen due to anelectric current being passed through the water. Generally, anelectrical power source is connected to two electrodes made from aninert metal such as platinum, which are placed in the water. Hydrogenwill appear at the negative electrode and oxygen at the positiveelectrode. In one embodiment, an electrolyte such as salt is added tothe water prior to electrolysis to increase the electrical conductivityof the water. Such equipment is commercially available and can providethe required quantities of hydrogen and oxygen gas.

The process of the invention is intended primarily for treatment ofhuman remains, but it may also be employed for treatment of animalremains, such as domestic pets, and biological material such ashazardous biological waste from a clinical or medical environment. Inthis specification, the term “domestic animal” should be understood tomeans domestic pets, for example, dogs, cats, and rodents.

The term “animal remains” should be understood to mean agriculturalanimals such as cows, sheep, goats and poultry, and larger animals suchas elephants and giraffes, where the remains are, typically,substantially intact.

In this specification, the term “biological material” should beunderstood to mean waste material that contains biological subjectmatter such as blood, serum, cells, tissue, organs or limbs. Examples ofsuch material include clinical and medical waste material, waste fromhospitals, and other types of biohazardous waste.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be more clearly understood by the followingdescription of some embodiments thereof, given by way of example only,with reference to the accompanying figures in which:

FIG. 1 is a flow diagram illustrating the process according to a firstembodiment of the invention;

FIG. 2 is a flow diagram illustrating the process according to analternative embodiment of the invention;

FIG. 3 is a flow diagram illustrating the process according to a furtheralternative embodiment of the invention;

FIG. 4 is an illustration of an apparatus according to another aspect ofthe invention.

FIG. 5 is a flow diagram illustrating a process according to anotheraspect of the invention;

FIG. 6 is a flow diagram illustrating a process according to anotheraspect of the invention; and

FIG. 7 is an illustration of an apparatus according to another aspectinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, and initially to FIG. 1, a flow chart isprovided illustrating the process of the invention, indicated generallyby the reference numeral 1. The process involves an initial freezingstage 20, where the remains are subject to a freezing process, asubsequent fragmentation stage 30, where the frozen remains are treatedto size reduce them to a particulate material, a drying stage 40 wherethe particulate material is heat treated to evaporate water from theparticulate matter, and then a pyrolysis stage 50 where the partiallyde-watered particulate matter is subjected to thermal decompositionconditions in the absence of oxygen to provide a biochar, which oncecooled is deposited in an urn. Each of the individual steps will now bedescribed in more detail.

In the Freezing (cooling) stage 20, the remains are placed in a coolingbath in a cooling vessel, and liquid nitrogen at a temperature of −196°C. is poured into the bath until the remains are completely immersed inliquid nitrogen. The remains are left immersed in the liquid nitrogenfor a period of 1 hour, which is sufficient to reduce their coretemperature to −100° C. or less. The chilled remains are then removedfrom the bath and cooling vessel for further processing. It will beappreciated that other methods of cooling the remains will be available,for example immersing them in liquid helium or liquid hydrogen or othercryogenic liquids or gases.

In the fragmentation (size reduction) stage 30, the chilled remains aresubjected to a size reduction process where the remains are converted toa particulate matter having a particle size of about 10 mm. In thepresent embodiment, the chilled remains are subjected to a millingprocess which converts the remains to a particulate matter, which isthen passed through one or more screens to ensure that the particulatematter has the desired average particle diameter of about 10 mm. Thescreening also removes large metal objects from the particulate, forexample metal prostheses such as replacement hips or joints. Theparticulate matter may also be subjected to a magnetic screen to removeferrous metal objects from the coarse particulate, prior to furtherprocessing. It will be appreciated that other methods of size reducingthe remains are possible, for example subjecting the remains toultrasound frequency or high pressure shock waves generated by theinitiation of combustible gases.

In the drying (de-watering) stage 40, the particulate matter generatedduring the size-reduction stage is subjected to a heat treatment toremove aqueous fractions, including water and water soluble toxins suchas embalming fluids and components of embalming fluids. The particulatematter is placed in a heater chamber, and heated at a temperature of upto 250° C. for a period of 30 minutes, whereupon most of the water(about 96%) in the particulate is removed by evaporation at atmosphericpressure. Aqueous fractions removed from the particulate are condensed41 and collected 42. This evaporation step has been found to beparticularly beneficial insofar as it reduces the energy input requiredto convert the particulate matter to biochar during the subsequentpyrolysis step. Ideally, the remains have about 8% water (w/w) at theend of the drying stage.

In the pyrolysis stage 50, the at least partially de-watered particulateis placed in a pyrolysis chamber and heated in the absence of oxygen toa temperature of 900° C. for a period of 1 hour. During this process,the particulate matter is thermally decomposed to biochar having aninitially high elemental carbon content. The pyrolysis processdenatures/destroys all bacteria, virus, and prions. Further, theresultant biochar is provided in a form free of mercury.

In a final storage stage 60, the biochar is placed in an urn capable ofbeing sealed to the environment, before being provided to the relativesfor final disposition.

Referring now to FIG. 2, an alternative embodiment of the process of theinvention is described in which parts described with reference to theprevious embodiment are assigned the same reference numerals. In thisembodiment, the process involves a further stage of mercury removal 70,which occurs after the pyrolysis stage 50. Mercury removal involvescleaning the gases generated by the pyrolysis or oxidation process in aspray as the gases exit the pyrolysis retort or combustion chamber in aflue, and thus condensing the mercury vapour to separate heavy metalsfrom the rest of the gases on the basis of mass differential. Anotherembodiment of the same invention would remove the mercury and othertoxic metals from the gas stream by cleaning it after the combustionprocess.

Referring now to FIG. 3, an alternative embodiment of the process of theinvention is described in which parts described with reference to theprevious embodiment are assigned the same reference numerals. In thisembodiment, the process involves a further stage of latent heat recovery80, where gases produced during the pyrolysis process are removed fromthe pyrolysis chamber, and are recycled back into the pyrolysis unit topower combustion or are stored in a gas storage chamber 81. The gasesremoved from the pyrolysis chamber may be fractionated prior torecycling, to separate out lower alkane combustible gases such asmethane or ethane.

Referring to FIG. 4, there is illustrated an apparatus for treatinghuman remains according to the invention, and indicated generally by thereference numeral 100. The apparatus 100 comprises a cooling vessel 120having a freezing bath 121 into which the remains (not shown) areplaced. A cryogenic fluid line 122 is provided for conveying liquidnitrogen from a liquid nitrogen storage or production system 123 to thecooling bath. Conveyor means 124 are provided to convey the chilledremains from the chamber 120 to a size reduction device 130, in thiscase a mechanical fragmentation device 131, where the frozen remains arefragmented to a particulate having a particle diameter of 10 mm. Aconveyor 132 screens the particulate to separate any matter having aparticle size greater than 10 mm. The particulate matter is thensubjected to a magnetic separation step 134 where any magnetic ferrousmetal objects, are removed from the particulate.

A conveyor 136 conveys the particulate matter to a drying chamber 140,where the particulate is heated to evaporate water from the particulate.The heating chamber 140 includes a water vapour removal line 141 fromwhich water vapour in the chamber is removed and conveyed to a condenser142 and water storage chamber 143. A conveyor 144 conveys the de-wateredparticulate to a pyrolysis chamber 150. The pyrolysis chamber 150includes an inert gas supply line 151 for charging the chamber with aninert gas prior to the start of the pyrolysis process, and optionally agas removal line 152 for removing gaseous pyrolysis by-products from thepyrolysis chamber during the pyrolysis process to a gaseous by-productstorage chamber 153. A further gas line 154 is provided for supply ofgas by-products to the pyrolysis chamber for combustion.

The apparatus 100 optionally also includes a water spray 160 adapted toclean gases evolved in the pyrolysis chamber 150 via a heat exchangerand flue system 161 and remove heavy metals, especially mercury, fromthe gases through condensation.

Various ways of performing the method of the invention are envisaged,including the methods shown in Tables 1 to 5 below:

TABLE 1 Method Steps A 1. Freeze the remains 2. Fragment the remains 3.Dry the remains 4. Pyrolyse—hydrous 5. Pyrolyse—anhydrous B 1. Freezethe remains 2. Fragment the remains 3. Dry the remains 4.Pyrolyse—anhydrous C 1. Freeze the remains 2. Fragment the remains 3.Dry the remains 4. Pyrolyse—hydrous

TABLE 2 Method Steps D 1. Fragment the remains 2. Dry the remains 3.Pyrolyse—hydrous 4. Pyrolyse—anhydrous E 1. Fragment the remains 2. Drythe remains 3. Pyrolyse—anhydrous F 1. Fragment the remains 2.Pyrolyse—hydrous

TABLE 3 Method Steps G 1. Dry the remains 2. Fragment the remains 3.Pyrolyse—hydrous 4. Pyrolyse—anhydrous H 1. Dry the remains 2. Fragmentthe remains 3. Pyrolyse—anhydrous I 1. Dry the remains 2. Fragment theremains 3. Pyrolyse—hydrous

TABLE 4 Method Steps J 1. Dry the remains 2. Pyrolyse—hydrous 3.Pyrolyse—anhydrous K 1. Dry the remains 2. Pyrolyse—anhydrous L 1. Drythe remains 2. Pyrolyse—hydrous

TABLE 5 Method Steps M 1. Pyrolyse—hydrous 2. Pyrolyse—anhydrous N 1.Pyrolyse—anhydrous

It will be appreciated that the methods described above may be embodiedin a variety of different apparatus without altering the method used.

Referring to FIG. 5, a flow chart is provided illustrating a processaccording to an embodiment of the invention relating to formalinremoval. The process involves an initial cooling stage 220, where theremains are subject to a cooling process, a subsequent size reduction(fragmentation) stage 230, where the chilled remains are treated to sizereduce them to a particulate material, an evaporation stage 240 wherethe particulate material is heat treated to evaporate volatilecomponents from embalming fluids and water vapour (including aqueousfractions from the remains) from the particulate matter, and then apyrolysis stage 250 where the partially de-watered particulate matter issubjected to thermal decomposition conditions in the absence of oxygento provide a biochar, which once cooled is deposited in an urn. In adistillation step 260, aqueous fractions are distilled to separate andrecover embalming fluids and toxic components thereof. Each of theindividual steps will now be described in more detail.

In the cooling stage 220, the remains are placed in a cooling bath in acooling chamber, and liquid nitrogen at a temperature of −196° C. ispoured into the bath until the remains are completely immersed in liquidnitrogen. The remains are left immersed in the liquid nitrogen for aperiod of 1 hour, which is sufficient to reduce their core temperatureto −20° C. or less. The chilled remains are then removed from the bathand cooling chamber for further processing. It will be appreciated thatother methods of cooling the remains will be available, for exampleimmersing them in liquid helium or liquid hydrogen or another cryogenicliquids or gases.

In the size reduction stage 230, the frozen remains are subjected to asize reduction process where they are converted to a particulate matterby means of a pressure wave generated through initiation of an oxygenand hydrogen gas mixture. The frozen particulate matter is thenoptionally screened to ensure that the particulate matter has thedesired average particle size. The screening also removes large metalobjects from the particulate, for example metal prostheses such asreplacement hips or joints. The particulate matter may also be subjectedto a magnetic screening process to remove small ferrous metal objectsfrom the coarse particulate, prior to further processing. It will beappreciated that other methods of size reducing the corpse are possible,for example subjecting in the corpse to ultrasound frequency or highpressure shock waves or other mechanical means.

In the de-watering stage 240, the particulate matter generated duringthe size-reduction stage is subjected to a heat treatment to removeaqueous fractions, including water and water soluble toxins such asembalming fluids and components of embalming fluids. The particulatematter is placed in a heater chamber, and heated at a temperature of upto 250° C. for a period of 30 minutes, whereupon most of the water(about 96%) in the particulate is removed by evaporation at atmosphericpressure. Aqueous fractions removed from the particulate are condensed241 and collected 242. This evaporation step has been found to beparticularly beneficial insofar as it reduces the energy input requiredto convert the particulate matter to biochar during the subsequentpyrolysis step.

In the pyrolysis stage 250, the at least partially de-wateredparticulate is placed in a pyrolysis chamber and heated in the absenceof oxygen to a temperature of 900° C. for a period of from 1 minute to 1hour. During this process, the particulate matter is thermallydecomposed to biochar having an initially high elemental carbon content.The pyrolysis process denatures/destroys all bacteria, virus and prions.Further, the resultant biochar is provided in a form free of mercury.

In the distillation stage 260, the aqueous fraction from the de-wateringstage 240 is subjected to fractional distillation to separate outembalming fluids (i.e. formalin) or components of the embalming fluids(i.e. formaldehyde) from the water. The separated embalming fluids orcomponents are stored 261 or recycled in the process via combustion toheat the pyrolysis chamber.

Referring now to FIG. 6, an alternative embodiment of the process of theinvention is described in which parts described with reference to theprevious embodiment are assigned the same reference numerals. In thisembodiment, the pyrolysis stage 250 includes a step of removal of liquidby products 251 which are circulated to the condensation stage 241 wherethey combine with the aqueous fractions from the de-watering stage 240,and are then subjected to the distillation stage 260 along with theaqueous fractions. In this embodiment, any embalming fluids orcomponents thereof that remain in the particulate matter followingevaporation are removed as a liquid by-product of pyrolysis, andseparated out and recovered in the distillation stage 260.

Referring to FIG. 7, there is illustrated an apparatus for treatinghuman remains according to the invention, in this embodiment to removeformalin and/or formaldehyde from the remains, and indicated generallyby the reference numeral 200. The apparatus 200 comprises a coolingchamber 220 having a cooling bath 221 into which the remains (not shown)are placed. A cryogenic fluid line 222 is provided for conveying liquidnitrogen from a liquid nitrogen storage vessel 223 to the cooling bath.Conveyor means 224 are provided to convey the chilled remains from thecooling chamber 220 to a size reduction device 230, where the chilledremains are size reduced in a pressure wave operation to a particulatehaving a particle diameter of 10 mm or less. A conveyor 232 screens theparticulate to separate any particulate matter having a particle sizegreater than 10 mm. The particulate matter is then subjected to amagnetic separation step 234 where any magnetic ferrous metal objects,are removed from the particulate.

A conveyor 236 conveys the particulate matter to a heating chamber 240,where the particulate is heated to evaporate aqueous fractions from theparticulate. The heating chamber 240 includes a vapour removal line 241from which the aqueous fractions in the chamber are removed as vapourand conveyed to a condenser 242 where the vapour is condensed. Thecondensed vapours are then transferred to a fractional distillationapparatus 260 where the aqueous fractions are subjected to fractionaldistillation to separate out and recover the formaldehyde or formalinand other toxic materials. A conveyor 244 conveys the de-wateredparticulate to a pyrolysis chamber 250. The pyrolysis chamber 250includes an inert gas supply line 251 for charging the chamber with aninert gas prior to the start of the pyrolysis process, and optionally agas removal line 252 for removing gaseous pyrolysis by-products from thepyrolysis chamber during the pyrolysis process to a gaseous by-productstorage chamber 253. A further gas line 254 is provided for supply ofgaseous by-products to the pyrolysis chamber for combustion.

In a further example, human remains are placed in a heating chamber, andsubjected to heating at a temperature of 150° C. for a period of timeuntil the water content of the remains is determined to be approximately8% (w/w). During the heating period, water vapour (including aqueousfractions from the remains) and formaldehyde (from the embalming fluid)are evaporated from the remains and withdrawn from the heating chamberto a condensation unit where they are condensed or dissolved, prior tobeing distilled in a distillation apparatus to separate out and recoversubstantially pure formaldehyde. The formaldehyde is stored prior tore-use to power the evaporation unit, or other steps in the process. Itwill be appreciated that the stored formaldehyde may also be stored andpackaged for re-use in industry.

The invention is not limited to the embodiments hereinbefore describedwhich may be varied in construction and detail without departing fromthe invention.

1. A process for treating human remains comprising the steps ofsubjecting the remains to a pyrolysis in a pyrolysis chamber underconditions that convert the remains to biochar remains.
 2. The processof claim 1 comprising a further step of oxidation of the biocharsubsequent to the pyrolysis step.
 3. The process of claim 1 in which theremains are dried prior to pyrolysis.
 4. The process of claim 3 in whichthe remains are dried to have a water content of about 6-12% (w/w). 5.The process of claim 3 in which the remains are dried to have a watercontent of about 8% (w/w).
 6. The process of claim 1 in which theremains are fragmented prior to pyrolysis.
 7. The process as claimed inof claim 6 in which the remains are chilled prior to fragmentation bysubjecting the remains, ideally the intact remains, to a cryogenicenvironment to reduce the temperature of the remains to a coretemperature of −20° C. or below.
 8. The process of claim 1 comprisingthe steps of: subjecting the remains to a cryogenic treatment to reducethe core temperature of the remains to a temperature of −20° C. orbelow; subjecting the frozen remains to a fragmentation step to providea chilled fragmented material; drying the chilled fragmented materialfrom the particulate to reduce the water content and subjecting thepartially dried fragmented material to pyrolysis in a pyrolysis chamberunder conditions that convert the particulate material to biocharremains, whilst releasing the latent chemical energy within the remains.9. The process of claim 8 in which the step of pyrolysis generatescombustible gases which are removed from the pyrolysis chamber andre-cycled to power the pyrolysis and/or evaporation steps.
 10. Theprocess of claim 1 including a further step of removing mercury fromflue gases produced in the pyrolysis step, optionally by means of agaseous cleaning process.
 11. The process of claim 3 in which the dryingstep reduces the water content of the remains to 1-20% (w/w).
 12. Theprocess of claim 3 in which the drying step reduces the water content ofthe remains to 5-10% (w/w).
 13. The process of claim 1 in whichpyrolysis is carried out at a temperature of at least 800° C.
 14. Theprocess of claim 1 in which the pyrolysis step comprises an anhydrouspyrolysis step, or a hydrous pyrolysis step, or both anhydrous andhydrous pyrolysis steps.
 15. The process of claim 14 in which thepyrolysis step is carried out in two stages, a first hydrous stage wherethe partially de-watered particulate matter is heated in the absence ofoxygen and presence of water to generate a fully de-watered particulatematter, and a second anhydrous stage where the fully de-wateredparticulate matter is heated in the absence of oxygen and water.
 16. Theprocess of claim 1 including a further step of depositing the biocharremains in a container which may be sealed against ambient air.
 17. Theprocess of claim 1, wherein flue gases expelled from the pyrolysischamber are sprayed with an aqueous liquid, typically water, to condensethe mercury or other metals for recovery. 18-56. (canceled)